Tube straightener - GIF

[nova_robotics]

The tubes need to fit quite close to the radius of the tubing other wise the tubing will be deformed and may come out almost square

Nope. Works fine.

If it were collapsing the tube you wouldn't be able to slide it by hand.

[Frank S]

Nope. Works fine.

If it were collapsing the tube you wouldn't be able to slide it by hand.

I think you will find that in trying to straighten refrigeration copper you will want the radius to be close to matching, might get away with 1 size smaller tubing if you are careful. The whole point of straightening is not as much to make the length appear perfectly straight as it is to make the tube cylindrical again. Making them straight appeases the inspectors making it round insures good sweat connections easier and faster to cut with tubing cutters as well. I have seen coils of 3/4 & 1" copper that were flattened so much when coiled that inspectors would reject the whole coil if not for a device to make the tubing cylindrical again as it was de-coiled.
many HVAC guys have a powered machine to do this with drop in cassettes for each size of tubing. Plus having one for each size has another advantage there is no need to adjust the roller centerline for different sized tubing.
True enough an auto mechanic might only have a couple of sized straighteners for steel lines such as brake and fuel lines 1 for 3/16, 1/4,&5/16" and one for 3/8, 7/16, & 1/2" He might even use the same devices for running copper air lines in the cases of restoring antique trucks but he would also need 1 more to fit the 5/8 &3/4" air lines in that case. It wont matter if the copper is not absolutely perfectly cylindrical as his fittings will be flared connections anyway.